1. Technical Field
The present invention relates to a solar cell device including a translucent plastic material having a curved surface, and a manufacturing method thereof.
2. Description of the Related Art
Recently, solar cells have attracted much interest as clean energy sources. In particular, silicon solar cells, which have higher power generation efficiency, have been taken into consideration as the most potential power for high-end markets for housing, automobiles, and the like in terms of various installation methods and construction sites. A solar cell typically has solar cell units and a translucent member, and light having passed through the translucent member enters the solar cell unit.
Most of mainstream solar cell devices currently provided have a flat-shaped translucent member. That is, as illustrated in FIG. 15, planar stack 6 of a solar cell device including solar cell units 2 is fixed to a fixing target with frame bodies 7 provided at each of the both sides of planar stack 6 (see PTL 1).
On the other hand, a solar cell device in which a translucent member has a curved surface has also been proposed (PTL 1). Solar cell device 11 illustrated in FIG. 14 has solar cell units 2 and translucent plastic material 12 having curved surfaces at both lateral end portions, and is fixed to a fixing target with frame portions 14 at both the lateral end portions. When the solar cell device illustrated in FIG. 14 is tried to be fixed to an automobile roof, a tile-integrated or building material-integrated house, a ship, and the like, a gap occurs between a mounting portion of the solar cell device and a portion to be installed, making it difficult to bring it into close contact with the portion to be installed. As a result, wind and rain sometimes enter a space occurring between the mounting portion of the solar cell device and the fixing target. In addition, there occurs a useless space. Further, there is also a problem of impaired outer appearance.
Thus, the translucent member of the solar cell device is sometimes required to have a curved surface structure corresponding to the curved surface shape of a portion to be operated such as the automobile roof. However, the solar cell device including the translucent member having the curved surface structure lacks flexural strength at a location with smaller curvature radius of the translucent member, causing the problem of cracks or fractures easily occurring in the solar cell unit.
On the other hand, the translucent member of the currently provided solar cell device is often a glass substrate. Therefore, the weight of the solar cell device for an automobile roof is at least 30 kg. As a result, there occurs a problem of increasing fuel consumption of an automobile having the solar cell device mounted on the automobile roof. To solve this problem, there is also an attempt to provide a solar cell device having structural strength that can resist wind pressure using lightweight translucent plastic material 12 made of polycarbonate in place of the glass substrate (PTL 1).